The present invention relates to magnetic systems, and in particular to a method of controlling a magnetic flux of an electromagnetic, and also to constructions of an electromagnet which implement the method.
The proposed group of inventions can be used preferably in executing devices of electromechanical art, in particular in magnetic triggers, locking devices for blocking locks of safe boxes, automobiles, doors, etc. for preventing unauthorized penetration. In such constructions an electromagnet which performs the function of an electromechanical drive includes a magnetizing coil with a magnetic guide of a ferromagnetic material with at least one air gap. When a pulse of electric current is supplied to a winding of the magnetizing coil of ferromagnetic material of the magnetic guide, a magnetic flux which is generated in the magnetic guide attracts a movable armature. When the pulse signal of electric current is removed from the winding of the coil, the magnetic flux disappears, and as a result a holding force of the armature disappears as well, and then the armature is returned to an initial position under the action of a return spring.
A method of controlling a magnetic flux of an electromagnet with a relay characteristic is known, which is characterized by at least two stable levels of values of the magnetic flux in the magnetic guide, by supplying control pulses of electric current into the winding of a magnetizing coil with the possibility of obtaining an attracting force of the movable part of the magnetic guide (its armature), which is realized in an electromagnet with at least one air gap as disclosed for example in the German patent document DE 19639548 A1.
The known method is not sufficiently effective due to a high energy consumption, since the winding of the coil is always under current during its excitation and remains in this condition until the controlling pulse signal is removed. Moreover, the known method is relatively insufficiently effective due to a high number of emergency failures during the use, that are connected with failures of windings of the magnetizing coil which is always under current in an excited condition.
A method of controlling a magnetic flux of an electromagnet with a relay characteristic which is the closest for its technical subject matter and achieved results to the inventive method is characterized by at least two stabile levels of values of the magnetic flux in the magnetic guide, by supplying controlling pulses of electric current into the winding of the magnetizing coil with the possibility of obtaining an attracting force of a movable part of the magnetic guide (its armature) and which is realized in an electromagnet with at least one air gap is disclosed for example in the European patent document EP 0779454. in the known method of controlling a magnetic flux of an electromagnet, the above mentioned disadvantages are partially eliminated. However, the efficiency of the known method is still low for the same reasons.
The construction of the known electromagnet does not have a closed metal structure. As a result of this, its efficiency is reduced due to high magnetic flux of dissipation. Moreover, the construction of the known electromagnet does not have the property of a magnetic memory, since it does not provide the possibility of remagnetization of magnetically hard and magnetically soft materials of the magnetic guide. Therefore the known electromagnet does not provide a possibility of realizing the method of efficient control of the magnetic flux with two short-term pulses of different polarities in accordance with the principle “turned on-turned off”.
A known electromagnet which is closest as to its subject matter and achieved results to the present invention is an electromagnet of an electromagnetic drive of an executing device, preferably a magnetic trigger (contactor) which realizes the method of controlling a magnetic flux in a magnetic guide, in which a winding of the magnetizing coil is arranged with a movable armature and which has at least one air gap, wherein at least a part of the magnetic guide is formed as an insert of a magnetically hard material disclosed for example in the European patent document EP 07794540.
In the construction of the known electromagnet, a part of the armature is composed of a magnetically hard material, and the magnetic guide during the operation of the electromagnet forms a three dimensional closed metallic structure, so that losses of a magnetic flux due to dissipation are reduced. However, the efficiency of the known electromagnet is insufficient because the permanent magnet which is used in its magnetic guide is arranged with a rigid marking of the magnetic poles, and during the operation of the electromagnet the part of its magnetic guide which is composed of a magnetically hard material does not remagnetize. As a result, the magnet guide of this known electromagnet does not have the property to obtain a magnetic memory. In other words when there is no current pulse in the winding of the magnetizing coil, the magnetic flux in the magnetic guide of the known electromagnet practically is absent. In any event, it is insufficient for providing a required force of attraction and holding the armature. Therefore, the known electromagnet has the above mentioned disadvantages and in particular a high energy consumption, insufficient reliability during use, insufficient functionality.